Vice President Kamala Harris and former President Donald Trump will need to navigate the pitfall-filled debate of their political lives on Tuesday as each tries to persuade millions of voters and viewers that they're the one best suited to be president.
Harris, whose wave of momentum has brought Democrats back to a neck-and-neck presidential race, will have to prosecute the case against Trump while also laying out how her agenda could help the country -- particularly beleaguered middle- and working-class Americans.
Trump, meanwhile, has the task of casting his record on the economy and immigration as superior to Harris' while avoiding distracting personal attacks on Harris.
The showdown in Philadelphia is taking place months after the last debate ended President Joe Biden's reelection bid, sending Harris rushing to stand up an eleventh-hour campaign and Trump scrambling to figure out how to negatively define a new opponent voters are less familiar with.
"I think there's an outsized expectation of 'gosh, the last guy dropped out, let's watch it.' So, I think that there's a lot more at stake than normally I would ever say is at stake," said Sean Spicer, Trump's first White House press secretary.
"I'm not a huge believer that debates move the needle that much," he added, "but I do think that because of the nontraditional nature of what's happening right now, there's going to be an outsized degree of attention."
Democrats who spoke to ABC News said that Harris has two main goals: affirm to voters that she is ready to lead the country and the free world and to describe in more detail what policies she'd pursue as president.